Armstrong, BenMangtani, PunamFletcher, AstridKovats, SariMcMichael, AnthonyPattenden, SamWilkinson, Paul2015-12-082015-12-080959-8138http://hdl.handle.net/1885/28575OBJECTIVE To estimate the protection against death provided by vaccination against influenza. DESIGN Prospective cohort follow up supplemented by weekly national counts of influenza confirmed in the community. SETTING Primary care. PARTICIPANTS 24,535 patients aged over 75 years from 73 general practices in Great Britain. MAIN OUTCOME MEASURE Death. RESULTS In unvaccinated members of the cohort daily all cause mortality was strongly associated with an index of influenza circulating in the population (mortality ratio 1.16, 95% confidence interval 1.04 to 1.29 at 90th centile of circulating influenza). The association was strongest for respiratory deaths but was also present for cardiovascular deaths. In contrast, in vaccinated people mortality from any cause was not associated with circulating influenza. The difference in patterns between vaccinated and unvaccinated people could not easily be due to chance (P = 0.02, all causes). CONCLUSIONS This study, using a novel and robust approach to control for confounding, provides robust evidence of a protective effect on mortality of vaccination against influenza.This study was supported by the UK Medical Research Council. PM was funded by the Wellcome Foundation (grant number 051637) during this work. PW is supported by a public health career scientist award (NHS Executive, CCB/BS/PHCS031).© 2004 Armstrong et al; licensee BMJ Publishing Group Ltd. http://www.sherpa.ac.uk/romeo/issn/0959-535X ... "On author's personal website and open access repositories; Publisher copyright and source must be acknowledged; Must link to publisher version Publisher's version/PDF may be used; Creative Commons Attribution License or Creative Commons Attribution Non-Commercial License available (depending on requirement of funding agency); Authors retain copyright."agedcohort studiesgreat britainhumansinfluenza vaccinesinfluenza, humanprospective studiesregression analysisvaccination2004-09-1610.1136/bmj.38198.594109.AE2015-12-11